Trap for intravenous injection apparatus



May 20 1952 c. R. BAUER 2,597,699

TRAP FOR INTRAVENOUS INJECTION APPARATUS Filed July 7, 1949 IN VEN TOR. 0. ,4PM/cf P @Af/5P Patented May 20, 1952 UNITED TRAP FOR INTRAVENOUS INJECTIN i APPARATUS 4 f Clarence R. Bauer, Irvington, N. J.

Application July 7, 1949, Serial No. 103,351

This invention relates to apparatus forthe intravenous injection of medicinal liquids into the body. More particularly, the invention relates to an improved airv and sediment trap for preventing undesirable materials from entering the body with the injected liquid.

Although various devices have long been known for intravenously injecting medicinal liquids into the body, the most widely practiced process is known as the gravity-flow method. In that method a hypodermic needle is connected by rub- .ber tubing to a vessel containing the fluid to be injected. The vessel, which is usually provided with a flow-regulating cock, is suspended above the patient, and after the regulating cock, tubing and needle are completely Ypurged of air, the needle is properly inserted into the patients vein and the solution is allowed to flow by gravity into the vein.

In an alternativeprocess, known as the pressure-ow method, the liquid supply is subjected to air pressure provided by a compressor such as a pressure bulb, plunger or the like. Combinations of the gravity-flow and pressure-flow systems are also employed.

With any of these systems, asection of transparent tubing, such as a glass tube, is usually included in the tubing between the needle and liquid supply vessel to enable the doctor or attendant to observe the passage through the tubing of air bubbles which may be entrained with the liquid. When air bubbles are observed in the transparent tubing, the injection needle must be withdrawn immediately from the vein, the supply line purged of the air bubbles, and the needle reinserted into the vein to continue the injection. This operation is time-consuming and often painful and dangerous to the patient. If air bubbles enter the vein with the injection liquid, anair embolus is produced, usually resulting in severe pain to the patient, and if allowed to continue even for several seconds, the patient may receive a dangerous or fatal amount of air. Even though a constant watch is maintained, it is not infrequent for a severe or fatal air embolus tov develop within a matter of several seconds. The repeated purging of air from the tubing which connects the injection needle to the liquid supply results in a loss of valuable medicinal material, and as usually performed, the medicinal liquid is sprayed over the floor and equipment in the room where the patient is being treated.

The principal objects of this invention are to provide an improved trap for connection into the liquid supply line of an intravenous injection ap- 3 Claims. (Cl. 12S- 214) paratus for preventing the injection of air bubbles and other foreign materials with the injected liquid;I to provide such a trap which is light in construction and designed for stable. upright attachment to the patients arm or other body member; and to provide such a trap designed so as to eliminate the necessity of purging the supply line leading to the device.

Another objectof the invention is to provide such a trap having suiilcient capacity to trap therein all the air which normally becomes entrained in the liquid during the injection of a pint of liquid, a pint being the size in which injection liquids are usually supplied.

A further object of the invention is to provide such a device having a sediment trap as an integral part thereof.

These and other objects, novel features and advantages of the invention will become apparent from the following description of the embodiment thereof illustrated in the accompanying drawing, in which:

Fig. 1 is a top plan view of a trap constructed in accordance with this invention; and

Fig. 2 is a vertical section taken along the line 2-2 of Fig. 1. l

Referring to the drawing, the trap, which is advantageously made of glass or other transparent material such as the transparent plastic material sold under the trade-mark Lucite, comprises a cylindrical or cylinder-like tube 4 with its upper and lower ends closed. A pair of tubes or necks 6 and 'I are connected to substantially opposite sides of tube 4 adjacent the lower end thereof `and communicate with the chamber 5 therein.

The lower end of tube 4 is substantially iiat as shown at 4a, and extends slightly below the bottom of tubes 6 and 'l to provide a sediment receiving chamber 5a. The flat bottom of tube 4 and the connection of inlet and outlet tubes t and 'l adjacent the bottom of tube 4, with a substantial angle` between tubes B and 1, provide for stably mounting the device on the patients arm or other body member in an upright position by means of strips 8 of transparent adhesive tape or the like secured across tubes 6 and 1.

In use, inlet tube 6 is connected to the source of the injection liquid by means of rubber or transparent plastic tubing S which is iitted over a protruding flange 6a on the exterior of tube 6. J Outlet tube 1, having a flange 1a, is similarly connected directly to the hypodermic needle by means of a short section of tubing I0. With the bottle yof injection liquid suspended above the patient, and with the trap connected thereto and 3 to the hypodermic needle as described, the trap will be lled initially with injection liquid I I and it will be necessary only to purge the line between outlet tube 'I and the tip of the needle before inserting the needle into the patients vein. This purging is readily accomplished by allowing a small amount of the liquid to ow through tubing I and through the needle.

Air bubbles I2 which are entrained with the liquid as it enters the trap rise within chamber and displace some of the liquid from the upper end thereof as indicated in Fig. 2. Any foreign material I3 which is lighter than 4the liquid will also rise to the surface thereof within chamber and will be retained in this chamber. .Arlyioreign material I4 which is heavier than the"liqui'd will settle into the sump 5a. -.Consequent1.ithe liquid flowing out of chamber 5 will be .entirely free of air bubbles and entrained solidmaterials.

While the trap operates entirely satisfactorily l with the inlet and loutlet tubes '6 and '1 rconnect/ed to substantially opposite sides -of tube fi, Atribes 6 and 'I `may be arranged with ra smaller :angle between them. For example, as Yshown :in jphantom at 'I' `in Fig. l the outlet'tube rmay be dis- `posed iat an angle of less than 180, fbut fa'dva-n- 'tageously more than V90" Awith respect to therinlet than about 180, a counter-balancing support `rod-or tube I6 as shown in phantom in `Fig. 1"is advantageously connected to tube il vto provide fa completely stable support for 'the ltrasp. Of

course, the auxiliary support member -I 6 fdo'es -n'o't communicate with chamber 5.

I have found that the efliciency `of the `trap I disclosed is at least partially attributable to 'the relative proportions of the chamber i, the iinternal diameter of tubes 6 and 1, land the'deptho 'sump 5a. In order for the air bubbles and other foreign material to be completely removed lfrom Ythe liquid within the trap, the ratio ofthe diameter of chamber 5 to the internal diameter of tubes '6 land I should be at least about 4 to l, :and the ratio of the depth of sump 5a lbelow the bottom of tubes `(i and 1 to the internal diameter' of tubes 6 and 'I should be at least about 1 to 2. `.Tn `order` to provide chamber 5 with sufficient capacity to accommodate safely the amount of air which is normally entrained in fa `pint of injection liquid, when employing Seither the gravity-flow or pressure-flow systems lde.- scribed above, chamber 5 should have a vVol1-une .of at least about 6 cubic centimeters above the top of tubes 6 and 'I as indicated by the line I5.

.A trap such as shown in the drawing and which has proven highly efficient in service `has the following dimensions:

Inches Internal diameter of chamber 5 `1/ Internal diameter of tubes 6 and 1 l/s Depth of sump 5a below bottom of tubes 6 and I Y.- als Dome height of tube 4 above line I5 1-1/8 The trap illustrated in the drawing is between two and two and a half times larger than the trap described, but the proportions are approximately those specified above.

With an air and sediment trap constructed according to this invention, the intravenous injection apparatus, including such a trap, may be applied to a patient as described and the injection treatment may proceed Without further attention on the part of the doctor or operator. It will be unncessary to maintain watch over the flow of the injection liquid or to remove the injection needle from the patients vein to prefvent entry of `air bubbles -or other material with "the Jinfjection liquid, las Aair bubbles and solid foreign materials which become entrained with the injection liquid will be removed automatically as they pass through the trap.

l1. In an intravenous injection surgical appa- Jatus, 4an v,air and sediment trap comprising a 'transparent cylindrical tube disposed vertically aandsdeiinirrg 'a-ohamber closed at its upper and JOWBI' vends and having an inlet neck and an outlet neck communicating with the chamber within vsaid cylindrical -tube and adapted for connection iin *a Supply line yof the vinjection apparatuasaid'inletandoutlet'necks being both dis- 'jposedhorizontally and connected to said cylindrical'tubeadjacentto and in slightly upwardly spaced trela'tionto the lower end thereof with a substantial angle between said inlet and outlet vnecks,and the lower end of said cylindrical tube having a-substantially -ilat under surface where- 'fbysaidtrapi's adapted for stable mounting in an vupright positionon a 'body member of the patient by application o-f adhesive tape across the inlet 'and outlet necks.

'-2. In-ain intravenous injection fsurgical apparatos, an air and sedi-ment trap adapted to be mounted in @the :liquid ."supply line of the intra- Vvenous injection apparatus, said trap comprising 'a transparent cylindrical 'tube disposed vertically -andhavingits upper and vlower ends closed and having an inlet neck and an outlet neck extending horizontallywand communicating with the chan-ibex' within fsaid cylindrical tube in slightly upwardly fsp'a'ced relation to the bottom thereof 'and 'adapted for connection respectively to portions lof Athe liquid supply line between the source of supply and the injection needle, said inlet and `outlet necks being connected to said cylindrical tube adjacent the lower end thereof with an angle ofmorethan about `and less than about 'between said inlet and outlet necks, there 'being a counterbalancing support member connected y to said cylindrical tube adjacent the lower -en'd A'iheree'f in ithe horizontal plane of the said necks, and fthe lower end of said cylindrical tube being substantially vflat, whereby said trap is adapted for 'stablemounting in an upright positien for-ia body member of the patient by application of "adhesive itape across the inlet and outlet '-necks.

'3. In 'an intravenous injection surgical apparatus, an 'air and lsediment trap comprising a transparent cylindrical tube disposed vertically and having its upper and lower ends closed, said tube having an inlet neck and an outlet neck adapted 'for connection in a supply line between the 4source of vsupply and the injection needle of the apparatus, said necks being disposed horizontally and vconnected to said cylindrical tube adjacent the lower end thereof in slightly upwardly sliaced relation thereto and communicating with the chamber therein above the bottom of the chamber, 'said inlet and outlet necks being of 1a' lgreat deal smaller diameter than the cylindrical tube and extending from the cylindrical tube-at an angle of more than about 90 and less -thanabout 180 therebetween, and the lower por- 5 6 tion of the cylindrical tube below said inlet and Number Name Date outlet necks forming a sump for the collection 825,807 Clarke July 10, 1906 0f sediment. 1,140,720 Simons May 25, 1915 CLARENCE' R. BAUER. 1,724,693 Carpita, Aug. 13, 1929 5 1,775,362 Demarcus Sept. 9, 1930 REFERENCES CITED 2,002,008 Harris, Jr. May 21, 1935 The following references are of record in the 2,010,417 Schwab Allg.l 6. 1935 file 0f this patent: OTHER REFERENCES UNITED STATES PATENTS 10 Starbuck: "standard Practical Plumbing, Number Name Date page 281, Henley Publishing Co.. 1926. (C'opy in 473,591 Remy Apr.26,1a92 Scientific Library.) 

